Science 9
Chapter 8 Notes
Chapter 8 – Respiration p. 151-167
4 Gases in Air – oxygen, nitrogen, carbon dioxide and
water vapour.
- also dust, pollen, pollutants
Body wants only _______________
Respiratory System- organs and tissues that move ___
in & out of body.
Breathing is also called ____________________
Breathe in ___haling. Breathe out ___haling
Body uses _______ to release energy stored in food
molecules.
Cellular Respiration
Cellular respiration- the process by which your cells use
_____________ to release energy in your ________
Word Equation for Cellular Respiration (see p. 152)
Excretion –getting rid of excess ______________
Excretion takes place in the lungs, __________ and
_____________________.
Blood carries excess CO2 to your ______________&
gets rid of it when you breathe ___________.
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
Inhaled air
has
____% oxygen
and
____% CO2
Exhaled Air has _____% oxygen
and ___% CO2
When active, body cells use more ___________ and
produce more Carbon Dioxide (goes into ________)
Breathing Rate is the number of breaths you take in
one _______________
Nervous system checks level of ________ in the blood.
When CO2 is HIGH, breathing rate ___creases
When CO2 is LOW, breathing rate ___creases
When breathing rate higher, more _______is brought
into body and more ________is taken out. When CO2
level decreases, breathing rate returns to normal.
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
(Do Activity 8B-Bag Breathing)
(Do Review 8.1 on p. 154)
Label the diagram (Handout) using p. 155.
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
__________are the spongy organs that receive the air
you inhale.
Tiny air sacs in lungs are called ________________.
(singular ____________________)
Each alveolus-surrounded by _________ __________.
(O2 and CO2 can pass into and out of blood into the
alveoli)
Lungs located in the Chest Cavity (sealed chamber)
Rib cage - _________bones and ____________.
Diaphragm – large sheet of _____________ at bottom of
chest cavity.
(see class model of lung in the chest cavity)
How You Breathe
-muscles of rib cage & diaphragm tighten-pull ribs up,
make chest cavity volume bigger. Air rushes _____
from outside to fill empty space (vacuum) ( ___haling)
-muscles of rib cage & diaphragm relax. Rib bones
move inward. –Chest cavity volume gets ________er.
Air is now pushed ______ _______ the lungs.
( ___haling)
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
Outside of lungs stick to muscular walls of chest cavityby a thin layer of ______________. Prevents lungs from
collapsing.
(See Review 8.2 p. 159)
A Single Breath
-air enters through ____________ goes into the
___________ cavity. Tiny ___________ in nose filter
dust etc.
-air passes from nasal cavity throat  2 tubes
esophagus (takes food to _________________)
Trachea – carries ________ to the ___________.
When swallowing or drinking, flap called the
_____________________ closes over the
__________opening. (Food will not enter lungs)
Trachea has rings of ________________ (hold trachea
so always open)
All air passages covered with sticky _____________
Traps _________, ____________ & other small particles
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
Cilia – cells with tiny _______-like projections. Cilia
wave back & forth, moving mucus (with trapped
particles) AWAY from lungs mouth & nose.(coughed,
sneezed out or swallowed into dig. system)
Air passing through nasal cav. & trachea:
-warmed by tiny blood vessels near surface
-mucus adds moisture to this air.
Trachea branches into 2 tubes called ______________
Carry air into each lung. Bronchi divide into smaller
tubes in lungs  air goes into alveoli.
Exchange of Gases in Alveoli
Each alveolus – like tiny balloon with
air, surrounded by very small blood
vessels
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
-blood from all body parts arrives low in O2
high in CO2 (from cellular respiration)
After inhaling-alveolus filled with O2 rich air
Oxygen diffuses from inside alveolusblood
CO2 diffuses from blood  inside alveolus
Back to body cells
(high in O2
low in CO2 )
One alveolus
Blood
vessel
From body cells
Low in O2
High in CO2
So blood going to lungs has fresh supply of O2
The air inside the alveolus now has more CO2. This air
is breathed out. This gas exchange always taking place.
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
With pneumonia – Alveoli become filled with fluid or
blood-makes gas exchange difficult.
Body doesn’t get enough oxygen.
The Amount of Air in a Breath
Typical breath ~ 0.5 L (500 mL) of air
Vital Capacity – The ___________________ amount of
air you can move in and _________ of your lungs in one
breath.
Average adult vital capacity is ~ 4 L
Residual Air – Air that ____________ in the alveoli of
the lungs after a normal breath out (exhaling)
After about _______ normal breaths, all the residual air
is replaced.
(Do Activity 8E – Vital Capacity)
Taking Care of Your Respiratory System
-Fitness and Protection
-Exercise makes muscles of resp. system stronger
-makes it easier to breathe
-able to move more air when needed
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
Sometimes air contains harmful substances.
-Lung tissue is not tough-very soft and easily damaged
-harmful substances can enter your body through lungs
-masks often used in jobs with harmful subst. in air
-getting doctor care when needed (eg. infections)
-some harmful subst. – paint fumes, dust, asbestos
-fiberglass _________ _______
The Habit That Kills
Cigarette smoke –harms smoker and people around
(2nd hand smoke)
-hot smoke contains gases that condense into tars
in mouth and air passages.
-sticky tars stop cilia from moving (chemicals affect
& can kill cells of cilia) sticky material deposits in
air passages – no cilia to clean them. These
materials can damage tissue. Smokers cough-tries
to get rid of this.
- tar clogs delicate surfaces of bronchi and alveoli
less O2 can be absorbed into body.
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
-Cig. smoke also has carbon monoxide (CO)
CO takes place of O2 in blood-so the body gets less
O2 than it needs.
-nicotine in cig. smoke-absorbed into blood stream,
goes to brain within 7 seconds. Increases heartrate,
makes heart work harder-increases heart attack risk.
-nicotine extremely addictive drug. (brain acts like
you “need” nicotine to feel “normal”)
-Harm from smoking increases as years of smoking
increase.
-Cig. smoke contains several cancer causing
compounds (including tar, benzene etc.)
-Lung cancer hard to detect in early stages-tissue
soft & spongy so tumors do not cause pain at first.
-Later stages, cancer cells get into bloodstream and
spread to other organs – if too late becomes
untreatable.
-smokers (& people who are near) have more frequent
chest infections-eg. bronchitis (inflammation of small
air passages)
-cig. smoke damages cilia – more bacteria and viruses
enter lungs.
-Chronic bronchitis – some passages permanently
blocked—decreases surface area for gas exchange.
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
-emphysema – passages become blocked
- walls of alveoli break apart – become useless in
gas exhange.
- Hard to breathe
- heart is overworked –could cause heart disease.
- caused by cig. smoke, asbestos fibres, mining
dust.
-Why people smoke?
- harm not obvious at first
- advertising
- peer pressure
- nicotine causes “high” at first
- extremely additive – hard to quit.
Increased risk for smokers
Acute necrotizing ulcerative
Muscle injuries
gingivitis (gum disease)
Angina (20 x risk)
Neck pain
Back pain
Nystagmus
movements)
(abnormal
eye
Buerger’s Disease (severe Ocular Histoplasmosis (fungal
circulatory disease)
eye infection)
Duodenal ulcer
Osteoporosis (in both sexes)
Cataract (2 x risk)
Osteoarthritis
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
Cataract,
posterior Penis (inability
subcapsular (3 x risk)
erection)
Colon Polyps
to
have
an
Peripheral vascular disease
Crohn’s Disease
inflamed bowel)
(chronic
Depression
Pneumonia
Psoriasis (2 x risk)
Diabetes (Type 2, non-insulin
Skin wrinkling (2 x risk)
dependent)
Hearing loss
Stomach ulcer
Influenza
Rheumatoid arthritis (for heavy
smokers) [5]
Impotence (2 x risk)
Tendon injuries
Optic Neuropathy (loss of Tobacco Amblyopia (loss of
vision, 16 x risk)
vision)
Ligament injuries
Tooth loss
Macular degeneration (eyes,
Tuberculosis
2 x risk)
Function impaired in smokers
Ejaculation (volume reduced) Sperm count reduced
Fertility
women)
(30%
lower
Immune System (impaired)
in
Sperm motility impaired
Sperm less able to penetrate
the ovum
Menopause
(onset
1.74 Sperm shape
years early on average)
increased
Science 9—Chapter 8 Notes
abnormalities
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Science 9
Chapter 8 Notes
Symptoms worse in smokers
Graves’ disease
thyroid gland)
Asthma
(over-active
Chronic
rhinitis
(chronic
Multiple Sclerosis
inflammation of the nose)
Diabetic retinopathy (eyes)
Optic Neuritis (eyes)
Disease more severe or persistent in smokers
Common cold
Crohn’s Disease
inflamed bowel)
Pneumonia
(chronic
Tuberculosis
Influenza
Of 1,000 young Australian males who smoke, 1 will be
murdered, 15 will be killed on the road and 250 will be killed
before their time by tobacco.
In Australia in 1986, the following body organs were
removed from humans because of cancer caused by smoking:
521 lungs 148 gullets 71 tongues 221 voice boxes
82 stomachs 40 pancreases 68 wombs 85 bladders
115 kidneys and 161 miscellaneous body parts.
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
Cigarette smoking causes about 30% of cancers in
Canada and more than 85% of lung cancers.
Smoking marijuana
Marijuana cigarettes contain more tar than tobacco
cigarettes. People who smoke marijuana generally smoke
fewer marijuana cigarettes than people who smoke tobacco
cigarettes. But they tend to inhale more smoke per puff and
hold it in their lungs for as much as 4 times longer. Because
of this, some estimate that smoking 3 to 4 marijuana
cigarettes per day is roughly equal to smoking 20 tobacco
cigarettes. Marijuana users may have many of the same
health problems as cigarette smokers, including an increased
risk of cancer.
A team of Canadian researchers is reporting that women who
begin smoking within five years of starting to menstruate run
a significantly higher risk of developing breast cancer before
the age of 50 than women who don't smoke.
The five-year survival rate of a patient with lung cancer
is 15 per cent.
During their lifetime, 1 in 21 women will develop lung
cancer. Among men, 1 in 11 will develop lung cancer.
Science 9—Chapter 8 Notes
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Science 9
Chapter 8 Notes
45,000 Canadians die each year from tobacco-related
illnesses.
Nicotine is one of the most addictive substances in the
world. Eight of ten people who start smoking become
addicted.
Tobacco smoke contains more than 4000 chemicals. Many
are known to be harmful substances, including nicotine,
carbon monoxide, benzene, toluene, formaldehyde, acetone,
ammonia, cadmium and nickel.
More than 40 of these chemicals cause cancer in humans,
including 2-naphthylamine, 4-aminobiphenyl, polonium-210,
benzene, vinyl chloride, arsenic, chromium, and nickel.
Smoking causes cancer of the lung, oral cavity, pharynx,
larynx, esophagus, pancreas, kidney, urinary bladder, and
cervix. Recent evidence links smoking with cancer of the
large intestine and some forms of leukemia.
Science 9—Chapter 8 Notes
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